scholarly journals Changes in weed infestation of spring barley depending on variable pluvio-thermal conditions

2015 ◽  
Vol 68 (3) ◽  
pp. 233-240
Author(s):  
Roman Krawczyk ◽  
Roman Kierzek ◽  
Kazimierz Adamczewski

<p>The aim of the study was to analyze segetal weeds present in spring barley against the background of changes in pluvio-thermal conditions observed over the last 20 years (1993–2012) at the Field Experimental Station of the Institute of Plant Protection – National Research Institute in Winna Góra, Poland. Based on the mean value of the Sielianinov hydrothermal coefficient for the three months of spring vegetation, i.e., April, May, and June, three classes of pluvio-thermal conditions (very dry, moderately dry, humid) were distinguished. The phytosociological stability of weed species analyzed during the study period was assessed and the Shannon–Wiener index of species diversity in the communities and the Simpson dominance index were calculated for segetal weeds present in spring barley.</p><p>In the 20-year period analyzed, <em>Chenopodium album</em> and <em>Viola arvensis</em> exhibited the highest phytosociological stability and the highest abundance in the spring barley crop. Over the years analyzed, the dry spring vegetation periods were characterized by significant precipitation deficiency between late April and mid-June. In the years with favorable meteorological conditions, the weed species diversity measured by the Shannon–Wiener diversity index was higher than in the years with precipitation deficiency. In the very dry years, the species dominance index in the spring vegetation period was higher than in the wet years. The yield loss caused by weed infestation in the very dry years was higher by 6% as compared to moderately dry and wet years.</p>

2016 ◽  
Vol 69 (3) ◽  
Author(s):  
Eleonora Wrzesińska ◽  
Anna Komorowska ◽  
Grażyna Nurkiewicz

The condition and degree of weed infestation were determined in a spring barely crop grown in a short-term monoculture after mulching the soil with plants grown as a stubble crop (the control treatment without cover crop – lacy phacelia, white mustard, sunflower). The field experiment was carried out in 2010–2013 on good rye soil complex using a split-block design in four replications. The obtained results (the mean from all years of the experiment) showed that the stubble crop, especially sunflower, reduced the diversity of weed species without causing at the same time changes in weed species dominance. In all the control treatments of the experiment, <em>Chenopodium album</em> and <em>Fallopia convolvulus</em> were the dominant species. The degree of spring barley weed infestation depended on the species grown in the cover crop. White mustard and lacy phacelia slightly increased the number of weeds but their fresh matter significantly increased. However, the sunflower cover crop significantly increased the number of weeds without any substantial differentiation of their fresh mass.


2021 ◽  
Vol 20 (3) ◽  
pp. 546
Author(s):  
Zikriah Zikriah ◽  
Imam Bachtiar ◽  
Lalu Japa

The Pandanduri Dam has a function as a support for agricultural irrigation water and also supports community activities so that it will affect the quality of its waters. The quality of the water needs to be analyzed because it can affect the aquatic ecosystem. This study aims to determine the level of water pollution in the Pandanduri Dam based on the phytoplankton community from the Chlorophyta Division. This type of research is descriptive exploratory. Sampling was carried out at 5 stations that were haphazardly selected with ecological representativeness consideration. Phytoplankton data were analyzed using the abundance formula, Shannon-Wiener diversity index, PIELOU uniformity index, and Simpson dominance index. The phytoplankton from the Chlorophyta Division found in the Pandanduri Dam were 14 species that are Pediastrum duplex var. Gracillimum, Gonium sp. 1, Gonium sp. 2, Coelastrum reticulatum, Scenedesmus acuminatus, Cosmarium sp., Chlamydomonas nasuta, Chlamydomonas sp., Selenastrum capricornutum, Monoraphidium dybowskii, Monoraphidium contortum, Monoraphidium irregular, Westella botryoides, and Kirchneriella lunaris consisting of 4 orders (Sphaeropleales, Chlorococcales, Chlamydomonadales and Desmidiales) and 10 genera (Pediastrum, Coelastrum, Scenedesmus, Gonium, Cosmarium, Chlamydomonas, Selenastrum, Monoraphidium, Westella, and Kirchneriella). The species diversity index of 2.21 is classified as moderate diversity, the species uniformity index is 0.83 which indicates even species growth, and the species dominance index indicates that no species dominates with a value of 0.12. The level of water pollution in the Pandanduri Dam was found in the moderate pollution category (oligotrophic).


2021 ◽  
Vol 21 (2) ◽  
pp. 448
Author(s):  
Niswatul Audah ◽  
Lalu Japa ◽  
M. Yamin

Diatom class Bacillariophyceae are world wide distribution and commonly dominated the phytoplankton community. The community of diatom class Bacillariophyceae of the waters Tanjung Luar Fish Landing Based (FLB) has never been reported. This study aims to determine the abundance and diversity of diatom class Bacillariophyceae. The sampling sites were determined by using a systematic random sampling method. Data of diatom class Bacillariophyceae were analyzed for species abundance, species diversity index and species dominance index calculations. The results showed, that the abundance of diatom class Bacillariophyceae species were 322.000 ind/L (low category), the species diversity index of diatom class Bacillariophyceae was 2.162 (moderate category), and the species dominance index was 0.138 (none of species dominance).


2013 ◽  
Vol 66 (3) ◽  
pp. 89-94
Author(s):  
Maria Ziaja

The research on segetal flora and agricultural ecosystems has gained special importance in recent years, since they are an important element in biodiversity conservation. An evaluation of the status of the segetal flora was made on the basis of a study conducted in the period 1998–2002 in crop fields of four municipalities located in the Strug River valley in Podkarpackie Voivodeship. This research was carried out in root and cereal crops. Total species richness and the average number of species per relevé were determined in this study. In determining species diversity of the communities, the Shannon-Wiener diversity index (H’) was used. In cereal crops, the community <em>Vicietum tetraspermae typicum </em>was characterized by the greatest species richness (109 species), while <em>Vicietum tetraspermae consolidetosum </em>showed the lowest richness (57 species). In root crops, the association <em>Oxalido-Chenopodietum polyspermi </em>exhibited the greatest richness (78 species), whereas <em>Galinsogo-Setarietum typicum </em>the lowest richness (53 species). In the cereal communities, a total 149 of weed species were recorded, while in the root communities their total number was 97. The values of the Shannon-Wiener diversity index (H’) ranged from 3.10 to 2.42. The phytocoenoses <em>Oxalido-Chenopodietum polyspermi, Vicietum tetraspermae typicum,</em> and<em> Vicietum tetraspermae</em>, the<em> </em>variant with<em> Vicia grandiflora, </em>were characterized by the highest values of the Shannon-Wiener diversity index (H’), whereas the association <em>Galinsogo-Setarietum typicum</em> and the impoverished communities from the alliance <em>Aperion spicae-venti </em>showed the lowest values.


2019 ◽  
Vol 18 (3) ◽  
pp. 223
Author(s):  
Friesland Tuapetel ◽  
Delly DP Matrutty ◽  
Welem Waileruny

The waters surrounding Ambon Island is a potential fishing gound for demersal fish resources, yet information regarding species diversity is still slightly understood. This research aimed to analyze the diversity of species and size of demersal fish around Ambon Island oceans. Data was collected based on experimental fishing using fish trap at two locations, in northern and southern waters of Ambon Island. The data were collected by experimental capture using fishing gear at two locations, namely northern waters (March-April 2015) and south of Ambon Island (July-October 2016). Methods of demersal resource diversity analysis are several ecological indexes i.e. Shannon-Wiener diversity index, Pielou uniformity index, and Simpson's dominance index. The result showed that 21 family and 57 species with details of 35 species in the northern waters and 32 species in the southern water. Species diversity based on Shannon-Wiener Index (H´) ranged between 1,61-3,10 while species evenness index (E) was around 0,83-0,95. The abundance of demersal fish was not dominated by any fish species, showed by the average Simpson index of dominant (D) around 0,05-0,26.AbstrakPerairan Pulau Ambon termasuk daerah penangkapan sumber daya ikan demersal yang potensial, namun informasi ke-anekaragamannya masih sangat sedikit. Penelitian ini bertujuan untuk menganalisis kekayaan jenis dan keanekara-gaman ikan demersal di perairan Pulau Ambon. Pengambilan data dilakukan dengan cara penangkapan eksperimental dengan menggunakan alat tangkap bubu pada dua lokasi yakni perairan utara (Maret-April 2015) dan perairan selatan Pulau Ambon (Juli-Oktober 2016). Metode  analisis keanekaragaman sumber daya ikan demersal menggunakan bebe-rapa indeks ekologi yakni indeks keanekaragaman Shannon-Wiener, indeks keseragaman Pielou, dan indeks dominansi Simpson.  Hasil penelitian menunjukkan bahwa di perairan Pulau Ambon teridentifikasi 21 famili dan 57 spesies de-ngan rincian 35 spesies di perairan utara dan 32 spesies di perairan selatan. Status keanekaragaman jenis indeks Shannon-Wiener (H´) berkisar 1,61-3,10 sedangkan indeks keseragaman jenis (E) sebesar 0,83-0,95. Kelimpahan ikan demersal tidak ada yang dominan, ditunjukkan oleh indeks dominan Simpson (D) sebesar 0,05-0,26. 


2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Lisa Ernawati ◽  
M Sofwan Anwari ◽  
M Dirhamsyah

Gastropod is one the mollusk phylum that can adapted at the mangrove ecosystem. Gastropod are organisms that have an ecological role as forming detritus. The study aimed to examine species diversity of gastropods in the mangrove forest ecosystem of Sebubus Village, Paloh District, Sambas Regency. The study was conducted in April 2019, using the survey method. Observations found 6 families and 16 species of gastropods in the mangrove ecosystem. Gastropods species are Chicoreus capucinus, Nerita balteata, Neritina cornucopia, Nerita violacea, Cerithideopsilla alata, Cerithidiopsis quoyii, Cerithidea obtusa, Littoraria scabra, Littoraria undulata, Littoraria carinifera, Nassarius dorsatus, Cassarius dorsatus, Cassidula aurisfelis, Ellobium aurisjudae, Cassidula nucleus, Pythia plicata, and Ellobium gangeticum. Species diversity index of gastropod in zone 1 = 0.83, zone 2 = 0.73 and zone 3 = 0.79 in the low category. Species abundance index of gastropod in zone 1 = 15.3, zone 2 = 10.5, zone 3 = 15.8.  Species evenness index of gastropod in zone 1 = 0.32, zone 2 = 0.30 and zone 3 = 0.30 categorized as low. Species dominance index of gastropod in zone 1 = 0.20, zone 2 = 0.28 and zone 3 = 0.25 are categorized as low. Species similiarity index of gastropod in zone 1 and 2 = 91.67%, zone 2 and 3 = 80.00%, zone 1 and 3 = 81.48 are categorized very high.Keywords: Diversity, Gastropods, Mangrove Ecosystems


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Hellen K. Mandela ◽  
Mugatsia H. Tsingalia ◽  
Mary Gikungu ◽  
Wilbur M. Lwande

Pollination is an important ecosystem service in the maintenance of biodiversity and most importantly in food production. Pollination is on the decline due to habitat loss, exotic species invasions, pollution, overharvesting, and land use changes. This study analyzed the abundance and diversity of flower visitors’ of Ocimum kilimandscharicum in Kakamega forest with increasing distance from the forest edge. Data were collected through direct observation and sweep netting. Six study sites were identified along two transects each 2.5 km long and labeled A to F. Distance in metres from the forest edge to each site was A=221, B=72, C=83, D=198, E=113, and F=50. Sampling was done from 7:30 am to 4:00 pm, three days in a week for five months consecutively. Diversity indices of different flower visitors were calculated using the Shannon-Wiener diversity index. One-way analysis of variance was used to compare differences between sites and a two-sample t-test was used to identify mean significant differences in species diversity between the closest and the furthest sites. A total of 645 individuals belonging to 35 species were captured from 4 families. The highest diversity was at site F (H’= 2.38) which was closest to the forest edge and the lowest diversity was from site A (H’=1.44) which was furthest from the forest edge. Distance from the forest edge significantly influenced species diversity (F(3, 20)=14.67, p=0.024). Distance from the forest edge also significantly influenced species abundance between the furthest sites A, D, and E and the nearest sites F, B, and C to the forest edge (t=4.177; p=0.0312) and species richness (t=3.2893; p=0.0187). This study clearly demonstrates that Ocimum kilimandscharicum flower visitors play essential roles in pollination and their higher number of visits translates into higher numbers of seeds set. Many of these pollinators are associated with the forest and hence the need to conserve the Kakamega forest as a source pool for pollinators.


2021 ◽  
Vol 267 ◽  
pp. 01035
Author(s):  
Ziqi Zhang ◽  
Lei Yang ◽  
Dongxu Han ◽  
Hongyan Shen

An investigation of phytoplankton community and water quality for M River was conducted in December 2019.The results showed that 38 species of phytoplankton belonging to 6 phyla and 26 genera were collected. Among them, Bacillariophyta is the richest species, which accounted for 34.21%, followed by Cyanophyta with 26.32% and Chlorophyta with 28.95%. The density of phytoplankton was 63.0*106 inds/L which indicated as eutrophic water body. The highest density was Bacillariophyta, accounting for 51.03%. The Shannon-Wiener diversity index (H’) varied from 1.34 to 2.24, the Margalef Species diversity index (d) varied from 2.71 to 3.85, and the Pielou evenness index (J) varied from 0.38 to 0.67. According to the integrative analysis results of H’, d and J, M River water quality belongs to oligo-polluted, but individual sites belong to meso-polluted.


2019 ◽  
Vol 11 (7) ◽  
pp. 1941 ◽  
Author(s):  
Yuzhe Li ◽  
Jiangwen Fan ◽  
Hailing Yu

Grasslands in northern China form an important ecological barrier that prevents and controls desertification. The Beijing–Tianjin Sand Source Control (BTSSC) Project has been implemented to restore grassland in order to control sand sourced pollution. This study aimed to understand the impacts of four applied restoration practices on the productivity, composition, and species diversity of vegetation communities in the BTSSC Project. The results indicated the following: (1) All the restoration practices tended to increase the height and cover of communities, and the effect was most obvious where grazing was excluded; (2) total biomass (87%), above-ground biomass (164%) and below-ground biomass (58%) only increased consistently when grazing was excluded from the steppe; (3) fenced and grazing exclusion practice significantly increased the abundance of species in communities, but all the practices tended to decrease the evenness of species; and, (4) the correlation analysis revealed that the Shannon–Wiener diversity index, and Pielou evenness index, showed significant negative correlations with the above-ground biomass of grassland communities after restoration, while no significant relationships were shown in reference plots. Our comparison of applied practices in the BTSSC project revealed that grazing exclusion might be a high priority for more successful restoration in this region.


2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Imam Widhiono ◽  
Eming Sudiana ◽  
Darsono Darsono

Increases in mean temperature affect the diversity and abundance of wild bees in agricultural ecosystems. Pollinator community composition is expected to change along an elevational gradient due to differences in the daily ambient temperature. This study investigated the diversity and abundance of wild bees in an agricultural area along an elevational gradient in Central Java, Indonesia. Wild bees were collected using a sweep net in 40 green bean (Phaseolus vulgaris) cultivation sampling locations at seven different elevations (8, 108, 224, 424, 644, 893, and 1017 m above sea level). Species diversity was determined using the Shannon–Wiener diversity index. We identified 932 individuals from 8 species of wild bee belonging to 3 families. The family Apidae was predominant, with 6 species, while only 1 species was found from each of Megachilidae and Halictidae. Across the study sites, diversity increased with increasing elevation (H′= 1.4,D= 0.25, andE= 0.78 at low elevation toH′= 2.04,D= 0.13, andE= 0.96 at high elevation), and higher numbers of species were found at middle and high elevations. Species richness and abundance increased linearly with increasing elevation, and species diversity was highest at middle elevations.


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